<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>margin纵向重叠</title>
    <style>
        #header {
            height: 50px;
            background-color: hotpink;
            margin: 15px;
        }
        
        #bottom {
            height: 50px;
            background-color: skyblue;
            margin: 10px;
        }
    </style>
</head>

<body>
    <p id="header">div1</p>
    <p></p>
    <p></p>
    <p></p>
    <p id="bottom">bottom</p>
</body>

</html>